Cable TV is pretty much like the phone system used to be.
You are not allowed to connect your own equipment to your cable television lines. Your cable TV system has the ability to buy WebTVs that work on their system and rent
them to their customers. They use a different modem than
the WebTVs you can buy in stores. Cable systems have the
ability to sell this service as WebTV (as Rogers cable does
in Canada) or to offer substantially the same service
under their own name.
DSL service is not available in most of the US and is not
expected to be available soon. Verizon says only half of their Pennsylvania customers will be able to get DSL in 2005, and it will be 2015 before all are able to get it.
With DSL, you get a data connection - always on, and very
fast - as well as a voice connection. If you have a computer, you can connect on the data connection at the
same time that you connect with WebTV on the voice line.
Currently, nobody is selling WebTV with DSL modems to
the public.
Connecting your computer with DSL typically costs about
$100 for a DSL modem, installation charges which vary
widely from phone company to phone company, and a monthly
charge of about $40, which typically includes ISP services.
As an ISP typically costs $20, and two phone lines
typically costs more than $40, it may be considerably
cheaper to have the faster, always-on DSL service than
to use a dial-up modem.
An always-on connection presents a security risk.
Without a good firewall, anyone can examine the contents
of your computer's hard drive - and magazine reviews
of the inexpensive firewalls commonly used by consumers
indicate that they offer very little security. It
may make sense for you to turn off your computer when
you are not online. Then again, you may not object
when the kid across town sends copies of your income
tax return to your mother-in-law, copies of love
letters to your sunday-school teacher, copies of your
job-search letters to your boss....